Power consumption of integrated circuit devices (e.g., complementary metal oxide semiconductors (CMOS)) consists of two components: dynamic power (i.e., active power) and leakage power (i.e., static power). Dynamic power is the power required to switch the state of a device (i.e., to change the binary state of one or more device components from high to low or low to high). It is a function of capacitance, voltage, and switching frequency (e.g., P˜CVnF, where P is the dynamic power, C is the effective switch capacitance, V is the supply voltage, n is a coefficient greater than or equal to 2, and F is the switching frequency). Leakage power is the power consumed by a device when it is powered but not switching. In an integrated circuit device composed primarily of metal oxide semiconductor field effect transistors, the leakage power is an exponential function of the supply voltage.
Manufacturing processes may vary one or more physical parameters of devices that are formed according to the same design. These variations can affect delay (i.e., performance) of devices. Devices having delays that are extremely fast or slow with respect to an average one of the devices may not be desirable. In more technical terms, such devices may be at the “slow” end or the “fast” end of a process-voltage-temperature (PVT) space. A device at the “slow” end of the PVT space may not meet device delay requirements, whereas a device manufactured at the “fast” end of the PVT space may consume excessive dynamic power and/or leakage.
Selective voltage binning is a method for sorting manufactured devices to reduce the worst-case power consumption of a distribution of devices (e.g., parts). This technique varies the supply voltage based on the respective device delay of the devices in each voltage bin. Specifically, slower devices require a higher voltage to operate at maximum delay and faster devices require a lower voltage to operate within maximum power requirements. Therefore, slower devices are assigned to bins having greater voltage and faster devices are assigned to bins having lower voltage. This increases the fraction of the manufacturing distribution which simultaneously meet the design requirements for device delay and power consumption.
In selective voltage binning, testing is performed to determine the respective device delays of individual devices manufactured from the same design. For example, the temperature and voltage of the device may be fixed and the device delay of one or more components of the device may be measured. The devices are sorted into a plurality of voltage bins (i.e., groups) based on their respective device delays. If the delay of a particular device is low then the device is placed in a fast voltage bin corresponding to its delay. If the delay is high, then the device is placed in a slow device voltage bin corresponding to its delay. After the devices are sorted into bins, the range of acceptable supply voltages for operating the devices in each voltage bin is determined. In general, the nominal supply voltage for each bin decreases monotonically from the slowest bin to the fastest bin. Since both dynamic power and leakage power increase in proportion to the supply voltage, a reduction in the required supply voltage will reduce both dynamic and leakage power consumption and, thus, total power consumption.
When a particular device is provided to a customer, it is provided along with information indicating one or both of its assigned voltage bin and the required supply voltage corresponding to its assigned voltage bin. For example, the assigned bin or supply voltage requirements may be recorded within or on a device (e.g., by using a printed barcode or embedded non-volatile memory devices) for reference by a customer when setting up power supplies in a system using a particular device.